The present invention relates to an electric compressor having an inverter unit that is integrally equipped and drives an electric motor.
An electric compressor is known in the art which includes a housing accommodating therein a compression mechanism and an electric motor. The housing has an inverter unit that is integrated therewith and has mounted thereon electronic components for driving and controlling of the electric motor. The electronic components mounted on the inverter unit need to be insulated from the outside. For this purpose, the inverter unit is mounted to the housing of the electric compressor through a seal member to seal the electronic components. Generally, a gasket or an O-ring is used as a means for sealing the housing.
Japanese Patent Application Publication No. 2002-372152 discloses a structure for mounting a gasket, according to which a cover member is mounted to its mating member through the gasket without allowing the gasket to be dropped from the cover member. In the structure of the above-cited Publication, the gasket is used for sealing between a cylinder head cover (or the cover member) of an engine for a vehicle and a cylinder head (or the mating member) or sealing between an oil pan (or the cover member) and a cylinder block (or the mating member).
The gasket is of an annular shape and has connecting portions radially extending from predetermined positions of the annular gasket and pins extending upwardly and downwardly from the connecting portions. The cover member has therein an annular groove and a plurality of positioning holes. The mating member also has therein positioning holes. The gasket and the upper portions of the pins are respectively inserted in the annular groove and the positioning holes of the cover member for preventing the gasket from falling. Then, the lower portions of the pins are inserted in the respective positioning holes of the mating member and the cover member is fixed through the gasket to the mating member by fasteners.
Japanese Patent Application Publication No. 2005-233315 discloses a structure for mounting an O-ring to a casing or a cover of an engine or a pump that need be sealed. The structure in the above Publication prevents the O-ring from being removed or falling from an annular groove. The O-ring has a plurality of projections formed at predetermined intervals. A pump casing has therein an annular groove in which the O-ring is mounted. Cutouts are formed in the groove walls of the annular groove. The O-ring inserted in the annular groove receives an appropriate pressure force from the projections inserted in the cutouts of the groove, thus the O-ring being prevented from falling from the annular groove.
In the structures of the above two Publications, the seal members, or the gasket and the O-ring, are mounted in the annular grooves in the cover member and the pump casing, respectively, so that the seal members are prevented from being removed therefrom. However, in an electric compressor having an inverter unit integrated therewith, it is difficult to form in the housing or the inverter unit an annular groove for receiving a seal member because the inverter unit has therein many electronic components and yet there has been a demand for downsizing of the inverter unit. Therefore, the assembling of the inverter unit and the seal member is complicated and it is required such assembling be performed manually. Furthermore, when the seal member is handled manually, the seal member tends to be unstable, and correct positioning of the seal member relative to the housing becomes difficult. That makes the assembling work complicated.
The present invention is directed to providing an electric compressor that makes easy the assembling of an inverter housing while a seal member interposed.